• 제목/요약/키워드: Fibrillation

검색결과 497건 처리시간 0.023초

종이의 물리적 특성에 미치는 섬유의 찌그러짐 특성의 영향에 대한 CLSM 분석 (Analysis of Effects of Fiber's Collapse Index on Physical Properties of Paper Using CLSM)

  • 김서환;박종문;김철환
    • 펄프종이기술
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    • 제31권1호
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    • pp.46-51
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    • 1999
  • The most important effect of refining is believed as the internal fibrillation. The internal fibrillation is the separation of the fiber wall into several lamellae. The internal fibrillation results in fiber swelling as water penetrates the fiber wall. The increase in paper strength as a result of refining was due to delamination which made the fiber more flexible. Pulp fibers are refined to 20, 40, and 70$^{\circ}$SR freeness at Valley beater. Changes of Physical paper properties are analyzed depending on fiber wall thickness and fiber's collapse index at 2.5 and 5.6kg$_f$ refining load. At same $^[\circ}$SR freeness with 2.5kg$_f$ refining load, fiber wall thickness is increased further than at high 5.6kg$_f$ refining load. With higher fiber wall thickness by lower intensity refining load, higher internal fibrillation, flexibility, collapsability of fibers are achieved. Those effects improve WRV, tensile strength, and burst strength. Tear strength shows opposite trend to tensile and burst strength as usual.

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Lyocell 섬유소재의 알칼리 팽윤과 피브릴화 거동 (Swelling and Fibrillation of Lyocell Fibers in Water and NaOH Solution)

  • 민병길;정영진;김창환;오영세
    • 한국의류산업학회지
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    • 제1권1호
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    • pp.56-61
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    • 1999
  • Swelling and fibrillation of two kinds of lyocell, $Tencel^{(R)}$ and $Lyocell^{(R)}$, were investigated using polarizing and scanning electron microscope (SEM). $Tencel^{(R)}$ of a representative lyocell showed that loop tenacity which is related to wrinkle and resilience of fiber does not show significant reduction in wet state. Two kinds of lyocell exhibited surprising degree of swelling in aqueous NaOH solution under free tension. Diameters of $Tencel^{(R)}$ and $Lyocell^{(R)}$ swelled up to 670% and 830%, respectively in the range of around 10% NaOH concentration. Molecular orientation estimated by birefringence also reduced remarkably in alkaline solution. Moreover, diameter and birefringence which changed in alkaline solution did not recovered to original level even after washing and drying. Fibrillation of $Lyocell^{(R)}$ fiber observed by SEM seems to be easier than that of $Tencel^{(R)}$. In order to understand the difference between $Tencel^{(R)}$ and $LyoceJl^{(R)}$, further study on the structure of the two fibers will be followed.

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청심연자탕으로 호전된 뇌경색을 동반한 심방세동 환자 치험 3례 (Case Report of Chengsim Yeunja-tang (CYT) for Atrial Fibrillation with cerebral-infarction.)

  • 김정철;오성원;송창훈;이슬희;정종진;김종윤;선승호
    • 대한한방내과학회지
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    • 제27권3호
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    • pp.751-761
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    • 2006
  • Atrial fibrillation (AF) is a common arrhythmia that is a potent independent risk factor for stroke. The incidence of AF increases with age and most affected people have underlying cardiac disease. An aging society increases the incidence of AF patients. The case was designed to evaluate the improving effect of Chengsim Yeunja-tang (CYT) for atrial fibrillation (AF) with Cb-infarction patients. This patient was treated with CYT and had significant improvement in symptoms and change of EKG. -Heart rate decreased in patients with higher than normal heart rate -RV5+SV1 voltage decreased (LVH improved) -Arrhythmia remained steady. -Palpitation. chest discomfort, dyspnea, headache, dizziness diminished. Results suggest that CYT is an effective treatment for Taeumin AF patients.

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심실빈맥/심실세동 분류를 위한 NEWFM 기반의 퍼지규칙 추출 (Extracting Fuzzy Rules for Classifying Ventricular Tachycardia/Ventricular Fibrillation Based on NEWFM)

  • 신동근;이상홍;임준식
    • 인터넷정보학회논문지
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    • 제10권2호
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    • pp.179-186
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    • 2009
  • 본 논문은 가중 퍼지소속함수 기반 신경망(Neural Network with Weighted Fuzzy Membership Functions, NEWFM)을 이용하여 Creighton University Ventricular Tachyarrhythmia DataBase(CUDB)의 심전도(ECG) 신호로부터 정상리듬(Normal Sinus Rhythm, NSR)과 심실빈맥/심실세동(Ventricular Tachycardia/Ventricular Fibrillation, VT/VF)을 분류하는 방안을 제시하고 있다. NEWFM에서 사용할 특징입력을 추출하기 위해서 첫 번째 단계에서는 웨이블릿 변환(wavelet transform, WT)을 이용하였다. 두 번째 단계에서는 첫 번째 단계에서 생성된 웨이블릿 계수들을 위상공간 재구성(Phase Space Reconstruction, PSR)과 첨단(Peak) 추출 기법의 입력 값으로 이용하여 2개의 특징입력을 추출하였다. NEWFM은 이들 2개의 특징입력을 이용하여 정상리듬과 심실빈맥/심실세동을 분류하였고 그 결과로 90.13%의 분류성능을 나타내었다.

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Testing the Mediating Effect of Appraisal in the Model of Uncertainty in Illness

  • Kang, Younhee
    • 대한간호학회지
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    • 제33권8호
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    • pp.1127-1134
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    • 2003
  • Background. Although there have been a great number of research studies based on the model of uncertainty in illness, few studies have considered the appraisal portion of model. Purpose. The purpose of this study was to test the mediating effect of appraisal in the model of uncertainty in illness. Additionally, this study aimed to examine the relationships among uncertainty, symptom severity, appraisal, and anxiety in patients newly diagnosed with atrial fibrillation. Methods. This study employed a descriptive correlational and cross-sectional survey design using a face-to-face interview method. Patients diagnosed with atrial fibrillation within the previous 6 months prior to data collection were interviewed by Mishel Uncertainty in Illness Scale-Community Form, appraisal scale, Symptom Checklist-Severity V.3, and State Anxiety Inventory. Results. A total of 81 patients with atrial fibrillation were recruited from two large urban medical centers in Cleveland, Ohio, U.S.A.. Symptom severity was the significant variable in explaining uncertainty ($\beta$=0.34). Individuals with greater symptom severity perceived more uncertainty. Uncertainty was appraised as a danger rather than opportunity, and those with greater uncertainty appraised a greater danger (p<.0l). While the appraisal of opportunity had the negative relationship with anxiety (r=-0.25), the appraisal of danger was positively associated with anxiety (r=0.78). The measure of goodness of fit (Q) of the model was .7863, and the significant test (X$^2$) for the Q was statistically significant (df =3, p<.00l). Accordingly, the overall mediating model of uncertainty in illness was proven not to be fit to the empirical data of patients with atrial fibrillation. Consequently, the mediating effect of appraisal was not supported by the empirical data of this study. Conclusion. The findings of this study were discussed in terms of their relevance compared with those of previous studies or theoretical framework and the plausible explanations on study findings. Lastly, in order to expand the present body of knowledge on uncertainty in illness model, recommendations for the future nursing studies were included.

$A{\beta}42$의 섬유화 및 독성에 대한 ${\beta}$-Asarone의 저해 효과 (Inhibition of $A{\beta}42$ Fibrillation and Toxicity with ${\beta}$-Asarone)

  • 김지아;이철원;이부균;이장천;안원근
    • 동의생리병리학회지
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    • 제28권3호
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    • pp.317-321
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    • 2014
  • Amyloid-${\beta}$ protein ($A{\beta}$) is a pathological component of Alzheimer's disease (AD) by participating in the senile plaque formation in the patient's brain. Although the exact mechanism of $A{\beta}$ toxicity is not fully elucidated, it is considered to be closely related to its fibrillation process. For prevention of AD, recent studies have suggested various small molecules which inhibit $A{\beta}$ fibrillation. In this report, ${\beta}$-asarone found in acorus plant has been investigated as an anti-amyloid molecule. ${\beta}$-Asarone was demonstrated to prevent in vitro fibrillation of $A{\beta}$ by inducing the oligomer formation that obviously decreased cytotoxicity. Therefore, ${\beta}$-asarone could be suggested as an inhibitory agent of $A{\beta}$ fibrillation and toxicity, which would help us not only to understand underlying principle of amyloidogenesis mechanism but also to develop a controlling strategy toward AD.

리오셀 직물 수지가공 효과와 염색성 (Dyeing Properties Resin Treatment Effects of the Lyocell Fabrics)

  • 유혜자;이혜자
    • 한국의류학회지
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    • 제32권7호
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    • pp.1095-1103
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    • 2008
  • The effects of resin finish and dyeabilities of four kinds of Iyocell fabrics that were manufactured by four kinds of pulps were investigated. The dyeabilities of Iyocell fabrics were similar, but differed from cotton fabric. In early stage of 30 minutes, cotton fabric was shown higher dye exhaustion ratio than Iyocell fabrics, however after then cotton fabric did not increase dye exhaustion, Iyocell fabrics increased continuously. At last, the dye exhaustion ratio of Iyocell fabrics were about 75% and that of cotton fabric was 65%. Two kinds of experimental procedures were applied for Iyocell fabrics. One was what the fabrics were treated with resins and washed with cellulase, and then dyed with reactive dyes. The other procedure was the fabrics were dyed with reactive dyes, and then applied the resin treatments and cellulase washing. After fibrillation and washing the undyed Iyocell fabric and the Iyocell fabric that was dyed with C.I.Reactive Red 120, their weight loss ratios were 3.5% and 2.8%, respectively. Dyeing with reactive dyes caused the crosslinking between cellulose and dyes and the crosslinking decreased fibrillation. The weight loss by enzyme washing of Iyocell fabrics decreased by the glyoxal and melamine resin treatments. The reduction of weight loss can be caused by fibrillation decrease. Dyeing and resin treating can be showed the synergic effect on the reduction of fibrillation. The effect of glyoxal resin on the reduction of fibrillation was a little better than that of melamine resin.

불쾌 증상 이론을 적용한 심방 세동 환자의 자가관리 (Self-care in Patients with Atrial Fibrillation Based on the Theory of Unpleasant Symptoms)

  • 김민영;이선희;박한종
    • 임상간호연구
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    • 제28권1호
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    • pp.23-33
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    • 2022
  • Purpose: This study aimed to identify the relationships among disease severity, anxiety, depression, social support, unpleasant symptoms and self-care among patients with atrial fibrillation based on the unpleasant symptom theory, and to examine the mediating effects of unpleasant symptoms. Methods: A cross-sectional study was conducted. The participants were 216 patients with atrial fibrillation who were being followed up on an outpatient basis at a university hospital in Seoul. Data were collected from November 1, 2020 to June 30, 2021, using self-report questionnaires. Data were analyzed using IBM SPSS/WIN 27.0 and PROCESS macro with 95% bias-corrected bootstrap confidence interval(CI). Results: The average age of participants in this study was 66.0years. Disease severity (β=10.19, p<.001) and depression (β=1.53, p<.001) had significant positive relationships with unpleasant symptoms. Also, unpleasant symptoms (β=-0.03, p=.006) had a negative relationship with physical activity, which is a subscale of self- care. Social support (β=0.06, p<.001) was positively related with physical activity. Unpleasant symptoms showed a mediation effect in the relationship between disease severity and physical activity (Bias corrected bootstrap CI -0.65, -0.04). Depression had an indirect effect on physical activity that was mediated by unpleasant symptoms (Bias corrected bootstrap CI -0.11, -0.00). Conclusion: The findings of this study suggest that integrated strategies including physical, psychological, and social factors should be considered to promote self-care in patients with atrial fibrillation.

관상동맥우회술 후 발생하는 심방 세동에 대한 분석 (Risk Factors of Atrial Fibrillation after Coronary Artery Bypass Grafting)

  • 황여주;박철현;전양빈;최창휴;이재익;박국양
    • Journal of Chest Surgery
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    • 제40권2호
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    • pp.90-96
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    • 2007
  • 배경: 수술 후 심방 세동은 심장 수술과 관련된 흔한 합병증으로, 저자들은 심폐체외순환기를 사용하지 않고 시행하는 관상동맥우회술(Off-pump coronary artery bypass graft; OPCAB)과 심폐체외순환기를 사용하여 시행하는 관상동맥우회술(On-pump CABG)를 시행 받은 환자에서 수술 후 심방 세동의 발생률을 조사하여 심폐체외순환기 사용 여부가 수술 후 심방 세동 발생에 미치는 영향과 위험 인자에 대해 알아보고자 하였다. 대상 및 방법: 2002년 1월부터 2005년 12월까지 관상동맥우회술을 시행받은 306명의 환자 중 OPCAB을 시행 받은 178명과 On-pump CABG를 시행받은 69명을 대상으로 하였다. 두 군에서의 수술 후 심방 세동 발생률, 수술 전, 중, 후 위험 요인을 조사하였고, 각각 두 군에서의 수술 후 심방 세동의 위험 인자를 분석하였다. 결과: 수술 전 환자 변수에 관하여 두 군 사이에 차이가 없었다. 수술 후 심방 세동은 OPCAB군에서 25예(14%), On-pump CABG군에서 15예(21%)가 발생하였고, 두 군 사이에 통계적 차이는 없었다. 수술 후 심방 세동의 위험 인자로는 OPCAB 군에서는 65세 이상의 고연령, 수술 후 3일 동안의 총 수액 투입/배출의 불균형, 수술 후 3일 동안의 출혈량이, On-pump CABG군에서는 65세 이상의 고연령, 수술 후 3일 동안의 총 수액 투입/배출의 불균형이 단변량 분석에서 의미 있게 나타났으며, 다변량 분석에서는 두 군 모두에서 65세 이상의 고연령만이 수술 후 심방 세동의 위험 인자로 분석되었다. 결론 : 수술 후 심방 세동은 관상동맥우회술 후 생기는 흔한 합병증으로 OPCAB은 수술 후 심방 세동의 발생을 줄이지 않는 것으로 생각되며, 65세 이상의 고연령은 심폐체외순환기 사용 여부에 관계없이 수술 후 심방 세동 발생과 관련이 있음을 알 수 있었다.

Effect of Mechanical Impact Treatment on Fiber Morphology and Handsheet Properties

  • Yung B. Seo;Kim, Dukki;Lee, Jong-Hoon;Yang Jeon
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2001년도 추계학술발표논문집
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    • pp.183-199
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    • 2001
  • Alternative way of shaping fibers suitable for papermaking was introduced. Impact refining, which was done simply by hitting wet fibers with a metal weight vertically, was intended to keep the fibers from shortening and to cause mostly internal fibrillation. Virgin chemical pulp, its recycled one and OCC were used in the experiment. It was noticed from the experiment that impact refining on virgin chemical pulp kept the fiber length and Increased bonding properties greatly, However, in the recycled fibers from the chemical pulp, fiber length and bonding properties were decreased. In OCC, which seems to contain fractions of semi-chemical pulp and mechanical pulp (GP), and which is recycled pulp from corrugated boxes, fiber length and bonding properties were decreased disastrously. We believe recycled cellulosic fibers (recycled chemical pulp and OCC in this case), which went through hornification, were less resistant to the mechanical impact than virgin chemical pulp. For virgin chemical pulp, impact refining allowed no significant fiber length shortening, high WRV, and high mechanical strength.

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